On Sat, Mar 8, 2025 at 03:23 PM, Kevin wrote:
Is there a particular current limiting power supply that you recommend for the sbitx?? I don't typically see HAM linear or switching power supplies with amp adjustments and the one that I have looks like a scientific bench model from the 60s.?
I use a Wantek switching power supply (30V 10A max.), which I filter with 2x 6 turns on FT140-43 ferrites and 1nF II 100nF capacitors at the input connector of the sbitx. The power supply is grounded only at the mains connector. The positive and negative wires run in parallel with 6 turns and the wire has a cross section of 2.5 mm2. The two capacitors are at the power connector. There are M4 threaded holes on the back of the device, one of which I use to attach the ground wire. The antenna is fed with RG8X coax and on the loop side there is 100/50 Ohm and a symmetrical/asymmetrical adapter on FT240-43 ferrites.
The final stage PSU has a current limiter of 30V 20A. On the PA power input there is 2x 6 turns on the same FT140-43 ferrite and the capacitors.
?
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Gyula HA3HZ
HA3HZ